package com.atguigu.gulimall.search.service.impl;

import com.alibaba.fastjson.JSON;
import com.atguigu.common.to.es.SkuEsModel;
import com.atguigu.gulimall.search.config.GulimallElasticSearchConfig;
import com.atguigu.gulimall.search.constant.EsConstant;
import com.atguigu.gulimall.search.service.MallSearchService;
import com.atguigu.gulimall.search.vo.SearchParam;
import com.atguigu.gulimall.search.vo.SearchResult;
import org.apache.lucene.search.join.ScoreMode;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.index.query.*;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.elasticsearch.search.aggregations.AggregationBuilders;
import org.elasticsearch.search.aggregations.bucket.nested.NestedAggregationBuilder;
import org.elasticsearch.search.aggregations.bucket.nested.ParsedNested;
import org.elasticsearch.search.aggregations.bucket.terms.ParsedLongTerms;
import org.elasticsearch.search.aggregations.bucket.terms.ParsedStringTerms;
import org.elasticsearch.search.aggregations.bucket.terms.Terms;
import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregationBuilder;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightField;
import org.elasticsearch.search.sort.SortOrder;
import org.springframework.stereotype.Service;
import org.springframework.util.StringUtils;

import javax.annotation.Resource;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;

/**
 * @author yhl
 * @create 2021-10-03 16:41
 */
@Service
public class MallSearchServiceImpl implements MallSearchService {

    @Resource
    private RestHighLevelClient client;

    // 去es进行检索
    @Override
    public SearchResult search(SearchParam param) {
        // 1.动态构建查询需要的DSL语句
        SearchResult result = null;

        // 1.准备检索请求
        SearchRequest searchRequest = buildSearchRequest(param);

        try {
            // 2.执行检索请求
            SearchResponse response = client.search(searchRequest, GulimallElasticSearchConfig.COMMON_OPTIONS);

            // 3.分析响应数据封装成我们需要的格式
            result = buildSearchResult(response, param);
        } catch (IOException e) {
            e.printStackTrace();
        }

        return result;
    }

    /**
     * 构建结果数据（将从elasticSearch中获取的数据封装）
     * @param response
     * @return
     */
    private SearchResult buildSearchResult(SearchResponse response, SearchParam param) {

        SearchResult result = new SearchResult();

        SearchHits hits = response.getHits();
        // 1.返回所有查询到的商品
        List<SkuEsModel> esModels = new ArrayList<>();
        if (hits.getHits() != null && hits.getHits().length>0){
            for (SearchHit hit : hits.getHits()) {
                String sourceAsString = hit.getSourceAsString();
                SkuEsModel esModel = JSON.parseObject(sourceAsString, SkuEsModel.class);
                // 给商品标题添加高亮
                if (!StringUtils.isEmpty(param.getKeyword())){
                    HighlightField sktTitle = hit.getHighlightFields().get("skuTitle");
                    String string = sktTitle.getFragments()[0].string();
                    esModel.setSkuTitle(string);
                }
                esModels.add(esModel);
            }
        }
        result.setProducts(esModels);

        // 2.所有的属性信息
        List<SearchResult.AttrVo> attrVos = new ArrayList<>();
        ParsedNested attr_agg = response.getAggregations().get("attr_agg");
        ParsedLongTerms attr_id_agg = attr_agg.getAggregations().get("attr_id_agg");
        for (Terms.Bucket bucket : attr_id_agg.getBuckets()) {
            SearchResult.AttrVo attrVo = new SearchResult.AttrVo();
            // 1.属性id
            long attrId = bucket.getKeyAsNumber().longValue();
            // 2.属性名字
            String attrName = ((ParsedStringTerms) bucket.getAggregations().get("attr_name_agg")).getBuckets().get(0).getKeyAsString();
            // 3.属性的所有值
            List<String> attrValues = ((ParsedStringTerms) bucket.getAggregations().get("attr_value_agg")).getBuckets().stream().map(item -> {
                String keyAsString = ((Terms.Bucket) item).getKeyAsString();
                return keyAsString;
            }).collect(Collectors.toList());

            attrVo.setAttrId(attrId);
            attrVo.setAttrName(attrName);
            attrVo.setAttrValue(attrValues);

            attrVos.add(attrVo);
        }
        result.setAttrs(attrVos);

        // 3.所有的品牌信息
        List<SearchResult.BrandVo> brandVos = new ArrayList<>();
        ParsedLongTerms brand_agg = response.getAggregations().get("brand_agg");
        for (Terms.Bucket bucket : brand_agg.getBuckets()) {
            SearchResult.BrandVo brandVo = new SearchResult.BrandVo();
            // 1.品牌的id
            long brandId = bucket.getKeyAsNumber().longValue();
            // 2.品牌的名
            String brandName = ((ParsedStringTerms) bucket.getAggregations().get("brand_name_agg")).getBuckets().get(0).getKeyAsString();
            // 3.品牌的图片
            String brandImg = ((ParsedStringTerms) bucket.getAggregations().get("brand_img_agg")).getBuckets().get(0).getKeyAsString();

            brandVo.setBrandId(brandId);
            brandVo.setBrandImg(brandImg);
            brandVo.setBrandName(brandName);
            brandVos.add(brandVo);
        }
        result.setBrands(brandVos);

        // 4.所有分类信息
        ParsedLongTerms catalog_agg = response.getAggregations().get("catalog_agg");
        List<? extends Terms.Bucket> buckets = catalog_agg.getBuckets();
        List<SearchResult.CatalogVo> catalogVos = new ArrayList<>();
        for (Terms.Bucket bucket : buckets) {
            SearchResult.CatalogVo catalogVo = new SearchResult.CatalogVo();
            // 得到分类id
            String keyAsString = bucket.getKeyAsString();
            catalogVo.setCatalogId(Long.parseLong(keyAsString));
            // 得到分类名
            ParsedStringTerms catalog_name_agg = bucket.getAggregations().get("catalog_name_agg");
            String catalog_name = catalog_name_agg.getBuckets().get(0).getKeyAsString();
            catalogVo.setCatalogName(catalog_name);

            catalogVos.add(catalogVo);
        }
        result.setCatalogs(catalogVos);

        // ========以上从聚合信息获取===========

        // 5.分页信息，页码
        // 当前页
        result.setPageNum(param.getPageNum());
        // 总记录数
        long total = hits.getTotalHits().value;
        result.setTotal(total);
        // 总页码
        int i = (int) (total % EsConstant.PRODUCT_PAGESIZE);
        int k = (int) (total / EsConstant.PRODUCT_PAGESIZE);
        int totalPages = i == 0 ? k : k + 1;
        result.setTotalPages(totalPages);

        // 设置页码导航
        ArrayList<Integer> pageNavs = new ArrayList<>();
        for (int j = 1; j <= totalPages; j++) {
            pageNavs.add(j);
        }
        result.setPageNavs(pageNavs);

        // 6.构建面包屑导航功能
        List<SearchResult.NavVo> collect = param.getAttrs().stream().map(attr -> {
            SearchResult.NavVo navVo = new SearchResult.NavVo();
            // attrs=11_7nm
            String[] s = attr.split("_");
            navVo.setNavValue(s[1]);
            // 远程调用获取对应的属性名
            navVo.setNavName(s[0]);
            return navVo;
        }).collect(Collectors.toList());

        result.setNavs(collect);


        return result;
    }

    /**
     * 准备检索请求
     * 模糊匹配，过滤， 排序，分页，高亮，聚合分析
     * @return
     */
    private SearchRequest buildSearchRequest(SearchParam param) {
        // 构建DSL语句
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        /**
         * 模糊匹配，过滤，
         */
        // 1.构建bool query
        BoolQueryBuilder boolQuery = QueryBuilders.boolQuery();
        // 1.1、must-模糊匹配
        if (!StringUtils.isEmpty(param.getKeyword())){
            boolQuery.must(QueryBuilders.matchQuery("skuTitle", param.getKeyword()));
        }
        // 1.2、bool-filter 按照三级分类id查询
        if (param.getCatalog3Id() != null){
            boolQuery.filter(QueryBuilders.termQuery("catalogId", param.getCatalog3Id()));
        }
        // 1.3 bool-filter 按照品牌id查询
        if (param.getBrandId() != null && param.getBrandId().size() != 0){
            boolQuery.filter(QueryBuilders.termsQuery("brandId", param.getBrandId()));
        }
        // 1.4 bool-filter 按照所有指定的属性进行查询

        // 1.5 bool-filter 按照库存是否有进行查询
        if (param.getHasStock() != null){
            boolQuery.filter(QueryBuilders.termQuery("hasStock", param.getHasStock()==1));
        }

        // 1.6 bool-filter 按照价格区间
        // 1_500/_500/500_
        if (!StringUtils.isEmpty(param.getSkuPrice())){

            /**
             * 价格区间
             * "range": {
             *             "skuPrice": {
             *               "gte": 0,
             *               "lte": 6000
             *             }
             */
            RangeQueryBuilder rangeQuery = QueryBuilders.rangeQuery("skuPrice");
            String[] s = param.getSkuPrice().split("_");
            if (s.length == 2){
                rangeQuery.gte(s[0]).lte(s[1]);
            }else if (s.length == 1){
                if (param.getSkuPrice().startsWith("_")){
                    rangeQuery.lte(s[0]);
                }

                if (param.getSkuPrice().endsWith("_")){
                    rangeQuery.gte(s[0]);
                }
            }

            // 将价格区间添加到filter中
            boolQuery.filter(rangeQuery);
        }

        // 1.7 bool-filter 按照属性查询
        if (param.getAttrs() != null && param.getAttrs().size() != 0){
            for (String attr : param.getAttrs()) {
                // attrs=1_5寸:8寸
                BoolQueryBuilder nestedBoolQuery = QueryBuilders.boolQuery();

                String[] s = attr.split("_");
                String attrId = s[0];
                String[] attrValues = s[1].split(":");
                nestedBoolQuery.must(QueryBuilders.termQuery("attrs.attrId", attrId));
                nestedBoolQuery.must(QueryBuilders.termsQuery("attrs.attrValue", attrValues));
                // 每个必须都得生成一个nested查询
                NestedQueryBuilder nestedQuery = QueryBuilders.nestedQuery("attrs", nestedBoolQuery, ScoreMode.None);
                boolQuery.filter(nestedQuery);
            }
        }

        // 将所有的查询条件封装
        sourceBuilder.query(boolQuery);
        /**
         * 排序，分页，高亮
         */

        // 2.1、排序
        if (!StringUtils.isEmpty(param.getSort())){
            // sort=saleCount_asc/desc
            String[] s = param.getSort().split("_");
            SortOrder order = s[1].equalsIgnoreCase("asc") ? SortOrder.ASC : SortOrder.DESC;
            sourceBuilder.sort(s[0], order);
        }

        // 2.2、分页
        sourceBuilder.from((param.getPageNum()-1)*EsConstant.PRODUCT_PAGESIZE);
        sourceBuilder.size(EsConstant.PRODUCT_PAGESIZE);

        // 2.3、高亮
        if (!StringUtils.isEmpty(param.getKeyword())){
            HighlightBuilder builder = new HighlightBuilder();
            builder.field("skuTitle");
            builder.preTags("<b style='color:red'>");
            builder.postTags("</b>");
            sourceBuilder.highlighter(builder);
        }
        /**
         * 聚合分析
         */

        // 1、品牌聚合 brand_agg
        TermsAggregationBuilder brand_agg = AggregationBuilders.terms("brand_agg").field("brandId").size(50);
        // 品牌的子聚合
        brand_agg.subAggregation(AggregationBuilders.terms("brand_name_agg").field("brandName")).size(1);
        brand_agg.subAggregation(AggregationBuilders.terms("brand_img_agg").field("brandImg").size(1));
        sourceBuilder.aggregation(brand_agg);

        // 2、分类聚合 catalog_agg
        TermsAggregationBuilder catalog_agg = AggregationBuilders.terms("catalog_agg").field("catalogId").size(50);
        // 分类聚合的子聚合
        catalog_agg.subAggregation(AggregationBuilders.terms("catalog_name_agg").field("catalogName").size(1));
        sourceBuilder.aggregation(catalog_agg);

        // 3、属性聚合 attr_agg
        NestedAggregationBuilder attr_agg = AggregationBuilders.nested("attr_agg", "attrs");

        // 聚合出当前所有的attrId
        TermsAggregationBuilder attr_id_agg = AggregationBuilders.terms("attr_id_agg").field("attrs.attrId").size(50);
        // 聚合分析出attr_id对应的名字
        attr_id_agg.subAggregation(AggregationBuilders.terms("attr_name_agg").field("attrs.attrName").size(1));
        // 聚合分析出attr_id对应的所有属性值
        attr_id_agg.subAggregation(AggregationBuilders.terms("attr_value_agg").field("attrs.attrValue").size(50));
        attr_agg.subAggregation(attr_id_agg);

        sourceBuilder.aggregation(attr_agg);


        String s = sourceBuilder.toString();
        System.out.println(s);


        SearchRequest searchRequest = new SearchRequest(new String[]{EsConstant.PRODUCT_INDEX}, sourceBuilder);
        return searchRequest;
    }
}
